1. Field of the Invention
The present invention relates to a fan assembly and a refrigerator having the same, and more particularly, to a fan assembly which can prevent vibration of a permanent magnet from being transferred to the outside and a refrigerator having the same.
2. Description of the Background Art
In general, refrigerators are appliances used to keep items frozen and/or refrigerated therein. A conventional refrigerator may include a refrigerator main body having a cooling chamber therein and a refrigeration cycle device having a compressor and a condenser, for maintaining a cooled state in the cooling chamber.
A machine chamber is disposed at a rear region of the refrigerator main body, and the compressor and the condenser are provided in the machine chamber. A fan for accelerating air flow may also be provided inside the machine chamber so as to facilitate the cooling of the condenser and/or the compressor.
An evaporator for supplying cooling air may be provided at one side of the cooling chamber of the refrigerator main body. A cooling air channel for conducting cooling air to the inside of the cooling chamber via the evaporator may be disposed in the refrigerator main body. A cool air blower fan for accelerating the flow of the cooling air may be provided at the cooling air channel.
As shown in FIG. 1, the fan assembly of the above-mentioned fans may include a fan 10 having a hub 11 and blades 21, a rotor 30 disposed to be received inside the hub 11, a stator 40 disposed inside the rotor 30 with a certain air gap therebetween, and a rotation shaft 50 disposed along a central longitudinal axis of the stator 40 and coupled to the rotor 30 and the fan 10.
A first bearing assembly 55 and a second bearing assembly 60 are provided at the respective ends of the rotation shaft 50 so as to rotatably support the rotation shaft 50. The first bearing assembly 55 is supported by being coupled to a casing (not shown), and the stator 40 is coupled at outer peripheries of each of the first and second bearing assemblies 55, 60.
The fan 10 is provided with the hub 11 having a cylindrical shape and a plurality of blades 21 protruding radially from the outer circumference of the hub 11 and spaced from each other in a circumferential direction. The fan 10 is implemented as an axial flow fan for blowing air in an axial direction and formed to have a propeller shape.
A coupling portion 13 is formed at one end of the hub 11 such that one end of each of the rotation shaft 50 and the rotor 30 is fitted thereinto. The rotor 30 is fitted inside the hub 11 by being closely contacted thereto (e.g., press-fit).
As shown in FIG. 2, the rotor 30 may include a frame 31 having a cylindrical shape and closely coupled at an inner surface of the hub 11, and a permanent magnet 33 coupled to an inner circumferential surface of the frame 31.
With this configuration, when power is applied to the stator 40, a torque is generated by interaction of the stator 40 and the permanent magnet 33, thereby rotating the rotor 30 and the fan 10 centering around the rotation shaft 50.
However, in the related art fan assembly, when the rotor 30 is driven for rotation, an electromagnetic excitation force generated in the air gap between the stator 40 and the rotor 30 vibrates the permanent magnet 33, and the vibration of the permanent magnet 33 is transferred to the outside through the fan 10 coupled directly in contact with the frame 31 housing the permanent magnet 33, thereby generating noise as well as reducing the durability of the constituting elements.
In addition, if the period for use of the fan assembly has elapsed, when the rotor 30 is driven by rotation, a relative rotation of the frame 31 with respect to the rotation shaft 50 may easily occur.
Further, if the permanent magnet 33 is coupled inside the frame 31, the permanent magnet 33 should be inserted inside the frame 31 in an axial direction, with attention to the position of the stator 40 in an axial direction. Accordingly, the insertion and fitting processes require a lot of time and effort, and if the centers of the permanent magnet 33 and the stator 40 are not axially aligned with each other, performance may be reduced.